Imaging apparatuses for diagnosis have been widely used to perform diagnoses of arteriosclerosis, and to perform preoperative diagnoses or to check postoperative results when intra-vascular treatment is performed using a high-performance catheter such as a balloon catheter and a stent.
The imaging apparatus for diagnosis can include an intra-vascular ultrasound apparatus for diagnosis (IVUS) and an optical coherence tomography apparatus for diagnosis (OCT), each of which has characteristics different from one another.
In addition, recently, an imaging apparatus for diagnosis (an imaging apparatus for diagnosis including an ultrasound transmitting and receiving unit which can transmit and receive ultrasound, and a light transmitting and receiving unit which can transmit and receive light) in which a function of the IVUS and a function of the OCT are combined together has been proposed (for example, refer to JP-A-11-56752 and JP-A-2006-204430).
The aforementioned imaging apparatus for diagnosis obtains tomographic images, which are orthogonal to the axis of a blood vessel. Therefore, a three-dimensional image can be generated by connecting the tomographic images in series. Once the three-dimensional image is generated, the tomographic image can be obtained at a free viewpoint and a free cross section.
Incidentally, a blood vessel which is positioned close to the heart, particularly, the coronary artery which is positioned so as to surround the heart is influenced by beating activities (hereinafter, simply referred to as “the cardiac beat”) of the heart, and the position thereof changes. Even though the continuous tomographic images along a vascular axis of the blood vessel are obtained by the above-described imaging apparatus for diagnosis, when there is vascular activity, for example, a site influenced by a cardiac beat resulting in vascular activity and a site not influenced do not smoothly connect to each other, thereby exhibiting unnatural images. In a case of an experienced doctor, it may be understood that the unnatural site implies an occurrence of an influence of vascular activity such as a cardiac beat. However, it can be difficult for other ones to judge the state.
JP-A-2005-253964 discloses a known technology of detecting cardiac beating activity and correcting the image. According to the technology, a position sensor is provided inside a catheter and scanned (IVUS or OCT) images are recorded together with positions detected by the position sensor. A movement locus of the catheter can be confirmed when the catheter is internally equipped with the position sensor. However, it can be difficult to determine whether the locus is caused due to the shape of a blood vessel or such a movement locus occurs due to a cardiac beat.